Consumer electronics, such as mobile phone, digital camera, PDA, MP3 player, have already become a part of our daily life. Owing to the development of technology, e.g., the growing integration capability of IC and the increasing precision of other electronic components, the volume of the technical electronics becomes smaller and smaller. Similarly, electronic products with larger power, such as power supply and UPS (Uninterruptible Power Supply) system, are also influenced to become miniaturized.
The major difference between electronic products with larger and smaller power is the power level of the power converter (such as transformer) because the power level is relative to the pressure resistance and the current resistance of the employed material, so it is difficult to reduce the volume as the power is large. Thus, the electronic products with larger power only can reduce the volume of other portions. The most common manner is to minimize the distance from the power I/O port and the signal transmission port to the main circuit board, so as to reduce the occupied space. Please refer to FIG. 1 which shows one kind of prior art. As shown, the connection wires 120 for the signal transmission port 110 have a small diameter with relatively greater flexibility, so that the connection between the signal transmission port 110 and the circuit board 100 almost can be disposed in any fashion and still complying with the safety regulation. However, for electronic product with larger power, as shown in FIG. 2 which shows another kind of prior art, because the transmitted current is relatively larger, the connection wires 120 between the power transmission port 130 and the circuit board 100 have a larger diameter for complying with the safety regulation, and as known, the greater the current, the larger the diameter. Further, for DC power transmission, owing to the more critical safety regulation, this situation becomes more serious. Therefore, if it wants to reduce the distance between the power transmission port 130 and the circuit board 100, just like the signal transmission port 110 in FIG. 1, the difficulty in arranging the connection wires 120 will increase since the large diameter reduces the flexibility thereof. So, the occupied space can not be reduced. Moreover, in practice, the larger diameter of the connection wire 120 also influences the assembling which not only wastes time and labor but also increases inconvenience. Therefore, for a long time, the volume of the electronic products with larger power can not be reduced effectively.
Consequently, since the larger diameter for greater current transmission is unavoidable under safety regulation, how to provide a structure for transmission in the power supply which can solve the problem described above and still comply with the safety regulation is really urgent.